Mercury, known as the most changeable of metals, was an emblem to the alchemists of transmutation itself, and the perceptible alterations of properties possible with small alterations in condition or environment.

whose speed might represent symbolically the common intelligence amongst major powers, in the sense of diplomacy, cleverness, and automatic understanding.

Indeed, the Norse god Loki, who is also a messenger is known also as a trickster, and represents wit and guile.

Windvane, symbolic ofchange and serendipity

Like a pun or an aphorism, the element mercury is meant to provide a sudden change of events, and for this reason was possessed of a certain irresistible allure to alchemists.

Often it was thought that simply combining mercury with lead would lead to a sudden transformation, if only the appropriate procedure were followed. Barring that, perhaps silver would shed some light on the situation, and then maybe sulpher to contribute the golden sheen...

But alas,

the symbolism of the elements did not bear out chemically, or at any rate it proved difficult to create gold from artificial representations of gold. Ultimately, the yearning for gold was not equal to its object, even if mercury remained as a kind of chimerical proof that transformation is sometimes possible.